Biology subjects

Liao, C.-J.

Publications and source records attributed to Liao, C.-J..

3 recordsLinked to original sources

bioRxiv2026

Sorghum ANTHRACNOSE RESISTANCE GENE3 Is a Non-Coding RNA That Confers Fungal Resistance through Enhanced Cell Death

The fungal pathogen Colletotrichum sublineola is a major constraint to sorghum production. The sorghum genotype IS18760 is resistant to multiple C. sublineola strains, but the genetic basis of this resistance is unknown. Bulk segregant analysis using whole-genome resequencing of a biparental mapping population identified a major resistance locus, designated ANTHRACNOSE RESISTANCE GENE LOCUS 3 (ARG3), associated with extensive cell death. Fine mapping delimited the ARG3 locus to a 30 kb interval containing three predicted protein-coding genes and one unannotated non-coding RNA gene. Among these, only the non-coding RNA gene showed consistent sequence polymorphisms between resistant and susceptible lines and elevated pathogen-induced expression in the resistant parent, suggesting that it underlies ARG3-mediated resistance. Regions syntenic to ARG3 across grass species contain conserved non-coding sequences enriched for H3K27me3 and H2A.Z chromatin marks, suggesting a conserved regulatory function. The resistance allele is absent from a 111-line sorghum pangenome. The resistant sorghum line harboring ARG3 and the corresponding avirulent pathogen strain originate from the same geographic region, suggesting co-evolution between host resistance and a prevalent pathogen strain. Phylogenetic analysis suggests that loss of resistance in susceptible lines may relate to insertion of a 12.4 kb repetitive sequence. Importantly, silencing of the ARG3 transcript in the resistant parental line abrogated resistance to C. sublineola, confirming that ARG3 non-coding RNA gene underlies the fungal resistance mediated by the ARG3 locus in IS18760. These lines of evidence show that ARG3 is an important target for resistance breeding and provide new insight into non-coding RNA-mediated disease resistance.

plant biology↗

bioRxiv2026

Thiol depletion and disruption of proteostasis contribute to the phytotoxicity of juglone

O_LIJuglone is the phytotoxic 1,4-naphthoquinone responsible for the allelopathic effects of black walnut (Juglans nigra), yet how plants perceive and respond to juglone remain poorly understood. C_LIO_LIWe conducted transcriptome profiling of rosettes and roots of Arabidopsis thaliana exposed to juglone from 30 min to 5 d, along with targeted metabolic profiling, biochemical assays, and untargeted proteomics to gain a systems-level understanding of how plants respond to juglone and to test hypotheses underlying its phytotoxicity. C_LIO_LIJuglone exposure induced expression of genes involved in glutathione, cysteine, and sulfur metabolism pathways, and in protein homeostasis. We found that juglone depletes the pool of reduced glutathione (GSH) in roots, in part, through conjugation. We demonstrate that via upregulation of transcription factors (NAC53 and NAC78), the response to juglone activates components of the proteasome stress regulon and triggers extensive proteome remodeling with engagement of the autophagy pathway when proteasome capacity is limited. C_LIO_LIOur findings (i) indicate that thiol depletion and disruption of proteostasis through juglones dual redox cycling and alkylation activities are central to its phytotoxicity, (ii) cast doubt on previous reports that juglone targets a specific enzyme in plants or other organisms, and (iii) provide insight into how the chemical properties of allelopathic quinones shape their ecological roles. C_LI

plant biology↗

bioRxiv2022

ANTHRACNOSE RESISTANCE GENE2 confers fungal resistance in sorghum

Sorghum is an important food and feed crop globally; its production is hampered by anthracnose disease caused by the fungal pathogen Colletotrichum sublineola (Cs). Here, we report identification and characterization of ANTHRACNOSE RESISTANCE GENE 2 (ARG2) encoding a nucleotide-binding leucine-rich repeat (NLR) protein that confers race-specific resistance to Cs strains. ARG2 is one of a cluster of several NLR genes in the sorghum differential line SC328C that is resistant to some Cs strains. This cluster shows structural and copy number variations in different sorghum genotypes. Different sorghum variants carrying independent ARG2 alleles provided the genetic validation for the identity of the ARG2 gene. ARG2 expression is induced by Cs, and chitin induce ARG2 expression in resistant but not in susceptible lines. ARG2-mediated resistance is accompanied by higher expression of defense and secondary metabolite genes at early stages of infection, and anthocyanin and zeatin metabolisms are upregulated in resistant plants. Interestingly, ARG2 localizes to the plasma membrane when transiently expressed in Nicotiana benthamiana. Importantly, ARG2 plants produced higher shoot dry matter than near-isogenic lines carrying the susceptible allele suggesting absence of an ARG2 associated growth trade-off. Further, ARG2-mediated resistance is stable at a wide range of temperatures. Our observations open avenues for resistance breeding and for dissecting mechanisms of resistance.

plant biology↗